Internet Draft
Jaehoon Paul Jeong
Jung-Soo Park
ETRI
Kenichi Mase
Niigata University
Youn-Hee Han
SAMSUNG Sait
Badis Hakim
LRI laboratory
Jean-Marie Orset
Telecom INT
draft-jeong-manet-addr-autoconf-reqts-01.txt
Expires: August 2004 14 February 2004
Requirements for Ad Hoc IP Address Autoconfiguration
Status of this Memo
This document is an Internet-Draft and is in full conformance with
all provisions of Section 10 of RFC2026 except that the right to
produce derivative works is not granted [1].
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Abstract
Ad hoc network has no built-in infra-structure for communication
among mobile nodes and operates in a stand-alone fashion, or may be
connected to the public Internet. All the nodes in ad hoc network
have the capability to maintain all the resources of the network in a
distributed fashion. One of the most important resources is the set
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of IP addresses configured with an addressing scheme. When a new
node joins a network, it has to be assigned an IP address as part of
its initialization. Since ad hoc network's topology may change
unpredictably, it is important to provide a resilient method for
providing IP address autoconfiguration. This document specifies the
requirements for IP address autoconfiguration in ad hoc networks
which have dynamic network topology.
Conventions used in this document
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this
document are to be interpreted as described in RFC 2119 [2].
Table of Contents
1. Terminology...................................................2
2. Introduction..................................................2
3. Scenarios.....................................................3
3.1 Join and Departure of Mobile Nodes........................3
3.2 Network Partitioning and Merging..........................4
3.3 Internet Connectivity.....................................4
4. Requirements for Ad Hoc IP Address Autoconfiguration..........5
5. IPv6 Considerations...........................................6
6. Security Considerations.......................................6
7. Open Issues...................................................7
8. Copyright.....................................................8
9. References....................................................8
10. Authors' Addresses...........................................9
1. Terminology
Two new terms are defined below:
Mobile Ad Hoc Network (MANET) A network where mobile nodes can
communicate with one another without
preexisting communication
infrastructure such as base station
or access point.
Autoconfiguration (Autoconf) Automatic configuration or
self-configuration.
2. Introduction
IP address configuration is a prerequisite for all the IP networking.
In ad hoc networks, such configuration should be performed in every
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mobile node, either manually or automatically. For convenience sake,
automatic configuration is needed in MANET [3].
In ad hoc networks, having dynamic network topology and being multi-
hop, the current automatic address configuration schemes used in the
Internet are difficult to adopt, such as DHCP and IPv6 stateless
address autoconfiguration. Also, MANET is an unadministered network
where there exists no network administrator who provides network
configuration information to users. In this environment, mobile node
should be able to self-configure its IP address.
This document specifies the requirements for IP address
autoconfiguration, considering MANET where there happen the network
partitioning and merging very often. Also, it considers the global
connectivity between the MANET and Internet.
3. Scenarios
There are the scenarios that should be considered in ad hoc IP
address autoconfiguration. Address autoconf protocol needs to deal
with the following aspects of the ad hoc environment.
3.1 Join and Departure of Mobile Nodes
When a mobile node joins a new MANET, an unused IP address is
allocated to or configured in the mobile node. When the mobile node
leaves the MANET, its address may become free for another.
Requirements:
o Address autoconf protocol MUST support timely autoconfiguration of
IP address for a mobile node.
o Address autoconf protocol MAY support mechanisms to probe
whether a mobile node moves into another MANET.
o Mobile nodes using address autoconf protocol MUST validate
allocated IP addresses when powering up or rebooting.
o Mobile nodes using address autoconf protocol MAY validate
allocated IP addresses when moving into a new network.
Implication:
o The information needed to autoconfigure IP address must be
collected or predefined in the MANET.
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3.2 Network Partitioning and Merging
Inevitably, a single MANET will be divided into two or more MANET
partitions. Also, these two or more MANET partitions, using the same
address autoconf protocol, will be connected together, creating a
single merged MANET. Prior to the merging, each partition has
independently allocated or configured addresses. After merging, two
nodes in the merged network may end up using the same address, thus
potentially creating address conflict.
Therefore, this network merging must be perceived by mobile node. If
address conflicts exist, they should be resolved.
Implication:
o The detection and resolution of address conflicts are the
indispensable part of address autoconf protocol operation.
Requirements:
o Ad hoc address autoconf protocol MUST detect and resolve address
conflicts in a timely manner and on an ongoing basis.
o Ad hoc address autoconf protocol MUST allow conflicted address
replaced with another.
o Ad hoc address autoconf protocol SHOULD minimize the damage, such
as loss of delivered packets, due to address replacement.
o Addresses SHOULD be allocated or autoconfigured in a way that
minimizes the probability that two or more nodes will have the
same address.
o In order to detect duplicate addresses, ad hoc address autoconf
protocol MAY get the aid of ad hoc routing protocol.
Through address autoconf protocol that detects and resolves the
conflicts on an ongoing basis, mobile nodes will benefit from
preventing misrouting due to duplicate addresses, and can be provided
consistent routing.
3.3 Internet Connectivity
A mobile node can want to communicate with a node placed in the
Internet. In such case, an Internet gateway providing the Internet
connectivity can exist in the MANET [4].
Requirements:
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o MANET MAY allow configuration of zero or more gateways for the
global connectivity to the Internet.
Implication:
o For host DNS name resolution, DNS information, such as the address
of recursive DNS server, should be delivered together with gateway
information.
4. Requirements for Ad Hoc IP Address Autoconfiguration
Ad hoc IP address autoconfiguration always includes the
configuration of an IP address and netmask (or prefix information in
IPv6); it may include some routing information (such as default route
or Internet gateway), considering the global connectivity to the
Internet. IP address autoconfiguration must take place before an IP
packet can be sent from one node to another. This section requires
that sufficient information be provided by an ad hoc address autoconf
protocol to allow IP packets to be sent to a unicast destination IP
address within a connected MANET partition, consisting of multi hops.
Requirements: An ad hoc address autoconf protocol
o MUST configure an appropriate netmask or prefix information.
o MUST allocate or autoconfigure unique IP addresses within an
connected MANET partition.
o MAY allow configuration of zero or more gateways for the global
connectivity to the Internet.
The following requirements are derived from applying Section 3.1 and
Section 3.2 to IP interface configuration.
Requirements: An ad hoc address autoconf protocol
o MUST be capable of providing IP address in a reasonable delay.
o MUST be capable of discovering whether an IP address is currently
in use.
o MUST detect and resolve IP address conflicts in a timely manner
and on an ongoing basis.
o MUST timely validate autoconfigured IP addresses when powering up
or rebooting.
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o MAY timely validate autoconfigured IP addresses when moving into a
new network.
o SHOULD be able to process the address conflict due to manual
address configuration.
o SHOULD minimize the influence of autoconf traffic on the ongoing
MANET communication performance.
o MAY get the aid of ad hoc routing protocol so as to detect
duplicate addresses.
o SHOULD minimize the modification of existing MANET routing
protocol.
o MAY get the aid of ad hoc routing protocol so as to minimize
the probability that two or more nodes will have the same address.
o When MANET partitions merge, ad hoc address autoconf protocol
SHOULD be performed in the way it avoids congestion caused by
messages sent for the purpose of duplicate address detection.
o SHOULD minimize the damage, such as loss of delivered packets,
due to address replacement for supporting the survivability
of upper-layer sessions, such as TCP.
o SHOULD allocate IP addresses to mobile nodes in a way that
minimizes the probability that two or more nodes will have the
same address.
o The reclamation of the addresses unused any more MAY be considered.
An IP address is assigned only for the duration the node stays in
the network. When the node departs the network, its IP address
MAY become available for assignment to other nodes. In this case,
address autoconf protocol SHOULD NOT immediately reuse the
released IP addresses as soon as they become available, in order
to reduce address conflicts.
5. IPv6 Considerations
IPv6 provides a mechanism that allows a host to generate a link-local
IP address Autoconfiguration [5][6]. Thus, this mechanism can be
extended to be suitable for MANET [7] or another can be redesigned
separately [8][9]. Also, it is necessary to discuss how to use IPv6
link-local address in a MANET which is logically one subnet.
6. Security Considerations
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Ad hoc IP address autoconf protocol MUST NOT be any less secure than
current IETF-Standard protocols related to IP address
autoconfiguration.
Because of their lack of infrastructure and their strong mobility,
mobile ad hoc networks are vulnerable to lots of security attacks.
Especially, address autoconf protocol is likely to be a good target
for attackers. For example, it can be the victim of Denial of
Service attacks in which a malicious node monopolizes all the
addresses or sends the response messages to create address conflicts
in the network. Consequently, an ad hoc IP address autoconf protocol
SHOULD, as much as possible, prevent such attacks.
Requirements: An ad hoc address autoconf protocol
o SHOULD prevent malicious nodes from monopolizing all addresses of
a network.
o SHOULD prevent malicious nodes from voluntarily creating IP
conflicts.
o SHOULD be able to identify nodes which belong to the network.
o SHOULD make sure that only authorized nodes are configured and
granted access to network resources.
Implication:
o A node SHOULD be able to prove at every moment, its membership of
the network.
7. Open Issues
There are some open issues about ad hoc address autoconfiguration as
follows:
o Is there any need to categorize requirements into some classes?
Most of the ad hoc address autoconf protocols proposed until now
can be categorized into two classes: a) Stateless address
autoconf protocol and b) Stateful address autoconf protocol.
We need to discuss if we should specify the respective
requirements according to each class.
o Should we make ad hoc address autoconf protocol completely
independent of ad hoc routing protocol or able to get the aid of
ad hoc routing protocol?
o Should we consider address conflict in the overlapped MANETs with
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two or more ad hoc routing protocols?
o Should we consider the coexistence of the address autoconf
protocol using authentication mechanism and that not using
authentication mechanism?
8. Copyright
The following copyright notice is copied from RFC 2026 [Bradner,
1996], Section 10.4, and describes the applicable copyright for this
document.
Copyright (C) The Internet Society July 12, 2001. All Rights
Reserved.
This document and translations of it may be copied and furnished to
others, and derivative works that comment on or otherwise explain it
or assist in its implementation may be prepared, copied, published
and distributed, in whole or in part, without restriction of any
kind, provided that the above copyright notice and this paragraph
are included on all such copies and derivative works. However, this
document itself may not be modified in any way, such as by removing
the copyright notice or references to the Internet Society or other
Internet organizations, except as needed for the purpose of
developing Internet standards in which case the procedures for
copyrights defined in the Internet Standards process must be
followed, or as required to translate it into languages other than
English.
The limited permissions granted above are perpetual and will not be
revoked by the Internet Society or its successors or assignees.
This document and the information contained herein is provided on an
"AS IS" basis and THE INTERNET SOCIETY AND THE INTERNET ENGINEERING
TASK FORCE DISCLAIMS ALL WARRANTIES, EXPRESS OR IMPLIED, INCLUDING
BUT NOT LIMITED TO ANY WARRANTY THAT THE USE OF THE INFORMATION
HEREIN WILL NOT INFRINGE ANY RIGHTS OR ANY IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE.
9. References
[1] Bradner, S., "The Internet Standards Process -- Revision 3", BCP
9, RFC 2026, October 1996.
[2] Bradner, S., "Key words for use in RFCs to Indicate Requirement
Levels", BCP 14, RFC 2119, March 1997.
[3] A. Williams, "Requirements for Automatic Configuration of IP
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Hosts", draft-ietf-zeroconf-reqts-12.txt, September 2002.
[4] Ryuji Wakikawa et al., "Global connectivity for IPv6 Mobile Ad
Hoc Networks", draft-wakikawa-manet-globalv6-01.txt, July 2002.
[5] T. Narten, E. Nordmark and W. Simpson, "Neighbour Discovery for
IP version 6", RFC 2461, December 1998.
[6] S. Thomson and T. Narten, "IPv6 Stateless Address
Autoconfiguration", RFC 2462, December 1998.
[7] Charles E. Perkins, Jari T. Malinen, Ryuji Wakikawa, Elizabeth M.
Belding-Royer and Yuan Sun, "IP Address Autoconfiguration for Ad
Hoc Networks", draft-ietf-manet-autoconf-01.txt, November 2001.
[8] Jaehoon Jeong et al., "Ad Hoc IP Address Autoconfiguration",
draft-jeong-adhoc-ip-addr-autoconf-02.txt, February 2004.
[9] Jaehoon Jeong et al., "Ad Hoc IP Address Autoconfiguration for
AODV", draft-jeong-manet-aodv-addr-autoconf-00.txt, February
2004.
10. Authors' Addresses
Jaehoon Paul Jeong
ETRI / PEC
161 Gajeong-dong, Yuseong-gu
Daejon 305-350
Korea
Phone: +82-42-860-1664
EMail: paul@etri.re.kr
Jung-Soo Park
ETRI / PEC
161 Gajeong-dong, Yuseong-gu
Daejon 305-350
Korea
Phone: +82-42-860-6514
EMail: pjs@etri.re.kr
Kenichi Mase
Niigata University
2-8050 Ikarashi,
Niigata-shi, 950-2181
Japan
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Phone: +81-25-262-7446
EMail: mase@ie.niigata-u.ac.jp
Youn-Hee Han
Samsung Advanced Institute of Technology
111, Suwon 440-600
Korea
Phone: +82-31-280-9577
EMail: yhhan@sait.samsung.co.kr
Badis Hakim
LRI Laboratory
University of Paris-XI
91405 Orsay cedex
France
Phone: 01-69-15-65-91
EMail: Hakim.Badis@lri.fr
Jean-Marie Orset
Institut National des Telecommunications
9, rue Charles Fourier
91 011 Evry
France
Phone: 01-60-76-44-75
EMail: jean-marie.orset@int-evry.fr
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